Stackable,disassemblable chair



Feb. 24, 1970 A G, plRE'r-n ETAL 3,497,262

. I STCKABLE, DISASSEMBLABLE` CHAIR Filed Nov. 27. 1967 2 Sheets-Sheet 1Fig.1

INVENTO:

Giancarlo PIRETTI Leonida CASTELLI ATTORNEY Feb. 24, A1970 Fnea Nov. 2v,1967 G. PIRE-rn ETAI- STACKABLE, DISASSEMBLABLE CHAIR 2 Sheets-Sheet 2 iF196 INvENToRs Giancarl PIRETTI Le onid CASTELLI ATTORNEY United StatesPatent O M 3,497,262 STACKABLE, DISASSEMBLABLE CHAIR Giancarlo Pirettiand Leonida Castelli, Bologna, Italy, as-

Signors to S.a.s. Anonima Castelli & C., Bologna, Italy, a limitedpartnership, a corporation of Italy Filed Nov. 27, 1967, Ser. No.685,768 Claims priority, application Italy, Sept. 12, 1967, 39,370/ 67Int. Cl. A47c 3/04, 7/70, 1/24 U.S. Cl. 297-239 5 Claims ABSTRACT 0F THEDISCLOSURE A stackable chair having a pair of inner solid members ofdie-cast light-metal alloy supporting the head and back, and a pair ofouter solid die-cast light-alloy elements in which the legs arereceived. The inner and outer elements on each side of the chair aregenerally elongated in the horizontal direction of the respective sideof the chair and are provided with mating longitudinal groove-andridgeformations and are interconnected by a bolt and expandable-sleeveassembly traversing the inner and outer elements. The outer element oneach side of the chair forms, at its upper side, a rest for theunderside of the corresponding element of a chair adapted to be stackedthereon, while the other elements also are provided with grooves adaptedto receive connecting pins for holding a number of chairs in laterallyadjoining relationship to form a row.

The present invention relates to a chair mainly intended for publicpremises for meetings and work, theater pits and amphitheaters ingeneral, economicoperational premises, oflices and the like, andconsisting mainly of light-metal die-cast elements, so designed that,when interconnected, they can be assembled with four screws only, whichlock and strongly fix in their proper positions the back and the seat ofthe chair without requiring the use of supplementary screws, supports,glues, mastics or other traditional systems.

OBI ECT OF THE INVENTION It is the object of the present invention toprovide an improved, readily assemblable seating unit havingconsiderable structural strength and rigidity and a minimum number ofparts.

The chair of the present invention, as described below, is of simpleassembly and easily disassembled and it is so designed that the die-castelements supporting the legs allow an easy lateral coupling orconnection to another like chair on both sides, so as to permit thejoining of chairs in a row; furthermore on the outside face of thedie-cast elements supporting the legs, it is possible, using the samefour screws used for the assembly, to attach, at least on one side ofthe chair, a bracket supporting an arm or a small wooden block, to beused as writing desk or as a rest, xed to a metal bracket enablingtilting, e.g. a hinge incorporated in the bracket.

The chair, with or without the above-mentioned lateral brackets, can beoverlapped without limit and, therefore, it is possible to pile a numberof chairs in a minimum possible space.

SUMMARY OF THE INVENTION The chair, according to the invention, consistsof at least four die-cast elements of Va light-metal alloy, of

3,497,262 Patented Feb. 24, 1970 ICC i.e. the inside faces, longitudinalgrooves adapted to receive corresponding projections formed along thelateral edges of the back and the seat of the chair; the diecastelements are rigidly joined two-by-two, by at least one tubularcylindrical bush or sleeve with slightly conical walls, which bush orbushes are directly inserted at the time of die-casting in the elementsupporting the legs.

At least one rigid tubular frame connects the coupled die-cast elements,having at least four ends free, in which are received conical lockingdevices capable of expanding and which can be tightened by means ofscrews from the outside of the above-mentioned die-cast elements.

'Ihe chair of the instant invention also includes a back or a seat,either separately or together with lateral edges whose projections canbe inserted into grooves formed in the above-mentioned die-castelements.

Furthermore the die-cast elements supporting the legs have on theexternal side of the chair at least an opening facing a recess casingreceived in the die-casting, the opening being designed to receive acoupling device for interconnecting the chairs in rows, the device ismade of metal, plastic, synthetic resin) material or the like, and onthe inside is provided with holes or slits suitable to support hooks,brackets or attachments of any sort for accessories such as paperholdingbaskets or planes on which can be located things with a limited surface.

The bracket, supporting either an armrest for the person seated on thechair or a desklike tiltable wooden plate or in general some otherplate, is fixed on the outer side of the die-cast element supporting thelegs by using the same screws which are used for assembling the chairwithout the brackets, these screws should be long enough to extendbeyond the bracket thickness and screw in to the female thread of theexpanding conical locking device.

SPECIFIC DESCRIPTION The invention is described below with reference tothe drawing in which:

FIG. l shows, in a side view, a chair with the bracket supporting atilting wooden planar writing desk and a paper-holding basket;

FIG. 2 shows, as seen from the front, the chair of FIG. 1;

FIG. 3 shows a detail of FIG. 2, enlarged;

FIG. 4 shows, as seen from the top, the detail of FIG. 3;

FIG. 5 shows, in a side view, a coupling device between the chairsaccording to the invention; and

FIG. 6 shows, as seen from the top, the device of FIG. 5.

The chair shown, includes two die-cast main elements 11 of light metalalloy, perfectly identical to one another, each element having thereininserted by imbedding at the time of die-casting, on one side, turnedtoward the door, two steel tubes forming the legs 12 (covered withplastic material 13 and with adjustable feet 14). On the other side,transversely and turned toward the chair inside, the chair is providedwith two tubular bushes 15, with slightly conical section walls, passingthrough corresponding holes of the die-cast element 17, which are(mirror symmetrical) specularly alike and each of which is coupled toone of the leg-supporting elements 11.

Each bush 15 is machined or, better, bored round the inside edge of itsown hole so that the die-cast elements 11 and 17, fitting perfectly oneto the other along the joining surface shaped as a tooth or step, willbe rigidly and indissolubly connected (see FIG. 3), to form the right orleft support of the chair; the axial hole 0f bush 15 is open for theentire length of the bush and is accessible at the faces of elements orpieces 11 and 17 that have remained free.

On the counter-posed surfaces of the die-cast elements 17 which arespecularly alike, that is to say that the right-hand element is mirrorsymmetrical to the left-hand element, we provide extended longitudinalgrooves adapted to receive the projections 19 along the lateral edges ofthe seat 30l and back 21; the latter consist of plywood bodies bent intoanatomical shape. The joining element between the right and the leftsupports of the chair, each formed by the rigid coupling of therespective elements 11 and 17, consists of a frame realized with twosections of steel tube 23, curved according to the lower profile of theseat and connected rigidly by means of cross-pieces 24, which are weldedor riveted. The frame has at its four free ends locking and expandingconical devices 25, of wellknown type, which are inserted into the axialholes of the bushes 15 from the interior of element- 17 and can betightened from the exteriorY of element 11, by means of screws 27 whichscrew into the axial thread of the expansion cone 27 (FIGS. 3 and 4) ofthe device 25.

When the four screws 26 are screwed in, after inserting projections 19of the seat 20 and back 21, into the grooves 18 of the elements 17, onethen establishes the traction and locks the conical expansion devices ofthe frame and, consequently, fully tightens all the pieces comprisingthe chair.

The die-cast elements 11 have, on the lower edge of the outer side ofthe chair, a recess 28 (FIG. l) of rectangular shape with the longerside arrested vertically, such opening being the transversalfree-section of a groove, produced in the piece at the time ofdie-casting. The opening is provided with a cylindrical enlargement 29having a diameter slightly larger than the width of the groove 28 and adepth of a few more millimeters, which on the part exceeding in depth issmaller in diameter and threaded. The recess formed by the groove 28followed by the cylindrical enlargement .29, is adapted t0 receive thehalf of the joint piece 30` (FIGS. 5 and 6) which forms the lateralconnecting or coupling means between two side-by-side chairs; the otherhalf of the jointpiece 30 is held in the similar recess in the otherchair to be connected. The length of the joint-piece 30 is such that,when set, can exert a slight traction, so that the adjacent faces of theside-by-side chairs are forced against each other. One of the twocylindrical ends of the piece 30, that is to say the one with a largerdiameter, has a hole 30 to allow the passage of the screw 31, which isthreaded into the deeper part of the cylindrical casing 29.

The same die-cast elements 11 have, on the surface towards the inside ofthe chair, two holes 32 (FIG. 2) into which can be inserted theoutwardly bent pins of brackets 33 for hooking a paper-holder basket 34onto the chair; on the lower surface another two holes are provided inwhich are inserted nylon mufiiing caps 36, which are useful as cushionswhen the chairs are stacked one over the other, such that the legs andouter light metal elements 11 of the stacked chairs are in respectiveplanes. In the nonlimiting example shown, the chair is shown to have abracket 37 supporting the woodenplane writing desk 38 on the right-handside. Bracket 37 for this desk consists of a tubular light-metal alloydie-cast element with two circular holes (at one end) which overlapthose of element 11, traversed by two tightening screws 26, as well as arecess identical to that formed by the groove 28 and the cylindricalenlargement 29, and at the opposed end the hinges 39, formed at the timeof die-casting, into which are inserted the pins 40 of the hinge whichpermits the tilting, within certain angles or fixed limits of the platewhich supports the Wooden desk 38. The bracket 37 which supports thewooden desk 38, is identical in its lower part to that which supportsthe arm and is applied on the external face of element 11 using the samescrews 26 needed for the tightening of the chair, such screws being longenough to traverse the thickness of the bracket and screw into thethread of cone 27 of the expansion locking device 25. To avoidtransverse oscillations, the bracket 37 is fitted with a tooth 42(formed at the time of die-casting) identical to one half of the jointpiece 30 which at the time of the assembly notches in, exerting a slighttraction in groove 28-29 of element 11 so that the bracket 37 remainsrigidly connected to the other elements of the chair, forming with theman integral body.

When bracket 37 is not used, the joint piece 30 will have a suiiicientlength to be locked, by a slight traction, into grooves 28-29 of thecorresponding elements 11 belonging to two side-by-side chairs.

The legs inserted into each element 11 form an acute angle, whose vortexis Vat the top, such that the top surface of each element 11, projectingfrom element 17 coupled, can offer a support to the muffiing caps 36 onthe lower surface of a chair overlapped with the first, since the lowerprofiles of elements 17 and 37 of the stacked overlying chair are al1contained within the outline of the corresponding elements of the chairunderneath; brackets 37 `are inclined towards the outer part of an angleso that the inside profile of the object to be supported by them, in aposition of minimum horizontal surface (desk lifted), falls entirely outof the vertical plane tangent to the external surface of element 11.Such angles and profiles permit stacking of the chairs, also when theyare fitted with the accessories 37.

What is claimed is:

1. A stackable chair comprising a pair of generally horizontallyelongated inner elements adapted to lie along opposite sides of aseating surface and composed of a diecast light-metal alloy and ofgenerally solid cross-section; a pair of generally elongated outerelements die-cast of a light-metal alloy and of generally solidcross-section respectively juxtaposed with said inner elements, theinner and outer elements along each side of said seating surface beingprovided with mating longitudinally extending groove-and-ridgeformations preventing mutual transverse displacement of the elements ateach side of said seating surface; detachable connecting means includinga pair of longitudinally spaced expansion members in one of the matingelements at one side of said seating surface and a respective screwtraversing the oher element of each side and anchored in each of saidexpansion members and tightenable to clamp the elements on each side ofsaid seating surface together; a pair of legs anchored in and extendingdownwardly from each of said outer elements; and a seat structuremounted on said inner elements and bridging same while forming saidseating surface, said seat structure including at least one pair oftubular frame members spanning said inner elements and anchored thereto.

2. A chair as defined in claim 1 wherein said inner elements are eachformed with a pair of transverse bores each receiving one of the tubularframe members and a respective expansion member whereby said expansionmembers clamp said tubular frame members to said inner elements and theinner and outer elements of each side of said seating surface togetherupon tightening of said screws, said outer elements each being formedwith laterally open notches alignable with corresponding notches ofadjoining substantially identical chairs, each pair of adjoining chairsbeing provided with a connecting member receivable in the notches of therespective outer elements.

3. A chair as defined in claim 2, further comprising a bracket mountedon the outer element on at least one side of the chair, said bracket andthe outer element on which it is mounted being formed with matingtooth-and-notch formations preventing twisting of the bracket withrespect to the outer element on which it is mounted, said bracket beingtraversed by the said screws traversing the outer element on which thebracket is mounted; and a writing desk swingably mounted on saidbracket.

4. A chair as defined in claim 2 wherein the legs of each pair extenddownwardly while including an acute angle with one another, each of saidouter elements being formed with a generally horizontal upper surfacebetween the legs of the respective pair and a lower surface providedwith muiing caps adapted to rest upon the upper surface of acorresponding outer element of a generally identical chair therebelow ina stacked condition of said chairs.

5. A chair as defined in claim 4 wherein said seat structure comprises ashaped wood seat and a shaped wood backrest spanning said innerelements, said inner elements having upwardly and rearwardly extendingarms carrying said backrest said frame members being interconnectedintermittent said elements, said legs being generally tubular and havinga covering of synthetic-resin material, said chair further comprisingself-adjusting feet on said legs.

References Cited UNITED STATES PATENTS 3,156,498 11/ 1964 Blodee 297-1623,227,487 1/ 1966 Blanchard 297-248 3,237,984 3/1966 Schneider et al297-248 3,281,184 10/1966 Axtell 297-248 3,328,075 6/ 1967 Albinson297-248 FOREIGN PATENTS 974,861 11/1964 Great Britain.

703,439 2/ 1931 France.

958,505 2/ 1957 Germany.

JAMES T. MCCALL, Primary Examiner U.S. Cl. X.R. 297-162, 248

